一株氯嘧磺隆降解菌分离鉴定及降解条件优化

Isolation and identification of a chlorimuron-ethyl-degrading bacterium and optimization of its degradation conditions

为解决氯嘧磺隆残留对土壤、水体污染及后茬敏感作物药害问题,为污染土壤微生物修复提供降解菌种资源,文中采用富集培养、逐级驯化等方法,从氯嘧磺隆污染土壤中分离到1株高效氯嘧磺隆降解菌T9DB-01,经形态特征、生理生化及16S rDNA序列分析,鉴定为假单胞菌Pseudomonas sp.。采用单因素实验探究温度、pH值、底物浓度、装液量和接种量对菌株T9DB-01降解氯嘧磺隆的影响,采用正交试验及验证,优化菌株T9DB-01对氯嘧磺隆降解条件。结果表明,在30℃,pH 8.0,底物浓度200 mg/L,装液量100 mL/250 mL,接种量4%的条件下,5 d后降解率达到93.7%。该降解菌株对氯嘧磺隆污染土壤原位生物修复具有一定的应用潜力。

In order to solve the problem of soil,water pollution and sensitive crop drug damage caused by chlorosulfuron residue,and to provide degradation strain resources for microbial remediation of contaminated soil,a chlorimuron-ethyl-degrading strain T9DB-01 was isolated from chlorosulfuron contaminated soil by the method of enrichment culture and step by step domestication.Strain T9DB-01 was identified as Pseudomonas sp.by morphological characteristics,physiological and biochemical analysis and 16S rDNA gene sequence analysis.The effects of temperature,pH value,substrate concentration,medium volume,and inoculation volume on the degradation of chlorsulfuron-methyl by strain T9DB-01 were investigated by single factor experiment.The degradation conditions of chlorosulfuron by strain T9DB-01 were optimized by orthogonal test and verification.Results show that 30℃,pH 8.0,inoculum 4%,liquid volume 100 mL/250 mL,substrate concentration of 200 mg/L,cultured for 5 d,the strain degraded 93.7%chlorsulfuron-methyl.The degrading strain has certain application potential for bioremediation of chlorsulfuron-contaminated soil.